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Re: GCC and memory segments
On Fri, 2003-09-26 at 02:04, Bernd Jendrissek wrote:
> Hmm, I'll look at SImode vs. PSImode. Is that the whole idea of partial
> integer modes - integer-like in most ways, but not actually an integer?
> IOW ideal for dealing with these weirdo pointers?
It has been used in the past for targets with odd-sized pointers and/or
segmented pointers. I don't see any such ports currently though. If
you look at the gcc-2.95 sources there is a mn10200 port that uses
PSImode. Using PSImode can have drawbacks, as you will need a lot of
special patterns for it, but I doubt that you can get segmented
addresses working otherwise.
> Could I make all pointers SImode/PSImode unconditionally, and then have
> GO_IF_LEGITIMATE_ADDRESS accept segment-less addresses depending on
> attributes? I'd have to expend some effort to *get* the attributes,
> though, no?
I think you'd have a lot of trouble getting back to the attributes from
a pseudo reg. You can certainly try something like this, maybe you can
figure out a way to make it work.
--
Jim Wilson, GNU Tools Support, http://www.SpecifixInc.com